The H.sub.2 -antagonist agents (hereinafter "H.sub.2 -antagonists") are routinely administered orally to patients suffering from gastrointestinal conditions such as ulcers, dyspepsia, various reflux indications and the like. Typically, the H.sub.2 -antagonist is delivered to the patient in tablet or powder-filled capsule form. Other liquid oral compositions such as syrups have also been proposed (see, U.S. Pat. No. 4,128,658 to Price et al.)
The H.sub.2 -antagonists are known to have an unpalatably bitter taste when ingested in any form other than solid capsule or tablet form. Additionally, capsules or tablets, which contain the drug in solid crystalline form, may exhibit non-uniform absorption characteristics because of multiple polymorphic forms. Some H.sub.2 -antagonists exhibit multiple polymorphic forms, and absorption characteristics can vary between these forms. In addition, polymorphic forms may not be stable, and may undergo transformation in the solid dosage forms. Alternative formulations targeted at resolving these disadvantages have been proposed. For example, PCT WO94/08560 and U.S. Pat. No. 5,068,249 to Schaeffer propose chewable or effervescent tablets. U.S. Pat. No. 5,008,256 to Long proposes formation of complexes of H.sub.2 -antagonists. U.S. Pat. No. 5,032,393 to Douglas et al. proposes resin adsorption. PCT WO94/08576, and U.S. Pat. Nos. 5,028,432 to Chopra et al. and 5,007,790 to Shell propose non-aqueous formations of H.sub.2 -antagonists in fats or oils. U.S. Pat. No. 5,229,137 to Wolfe proposes solid or liquid formulations which include an H.sub.2 -antagonist in combination with an antacid.
One H.sub.2 -antagonist, ranitidine, also has been reported to be incorporated into a non-aqueous composition comprised of a solid wax or oil such as "Miglyol" and a surfactant such as lecithin, and then filled into a gelatin capsule. See, C.A. 114(14) 129112. U.S. Pat. No. 4,585,790 to Padfield et al. proposes oral and injectable aqueous compositions of ranitidine having a pH range from 6.5 to 7.5. However these solutions are known to exhibit stability problems for injectable administration or when the solids are exposed to hygroscopic conditions. See, R. Tenaoka et al. J. Pharm. Sci. 82, 601 (1993).
Other methods of administering various pharmaceuticals, including other anti-ulcer drugs have been proposed. For example, U.S. Pat. No. 4,711,782 to Okada et al. proposes a microcapsule containing a drug and a drug retaining substance, which is formed by preparing a water-in-oil emulsion, thickening or solidifying the aqueous layer, and subjecting the resulting emulsion to in-water drying to provide a solid formulation.